<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    div{
        width:100px;
        height:100px;
        line-height: 100px;
        border-radius: 100%;
        border:2px solid rgb(6, 6, 14);
        text-align: center;
        font-size: 28px;
        position: relative;
        margin:50px auto;
    }
    div::after{
        display: block;
        content:"";
        width:20px;
        height:20px;
        background:rgb(171, 225, 10);
        position: absolute;
        right:-50px;
        top:0px;
        border-radius: 100%;
    }
    div:hover{
        animation: ceshi 5s linear infinite;
    }
    @keyframes ceshi{
        from{
            transform:rotate(0deg);
            -webkit-transform: rotate(0deg);
        }
        to{
            transform: rotate(360deg);
            -webkit-transform: rotate(360deg);
        }
    }
    @-webkit-keyframes ceshi{
        from{
            transform:rotate(0deg);
            -webkit-transform: rotate(0deg);
        }
        to{
            transform: rotate(360deg);
            -webkit-transform: rotate(360deg);
        }
    }
    </style>
</head>
<body>
    <div></div>
</body>
</html>